HVAC CONTRACTOR EXAM QUESTION
AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which component is responsible for circulating refrigerant through the
HVAC system?
A. Evaporator
B. Condenser
C. Compressor
D. Expansion valve
The compressor pumps refrigerant through the system, enabling heat
transfer.
2. What type of refrigerant is commonly used as a replacement for R-22 in
residential systems?
A. R-12
B. R-410A
C. R-134a
D. Ammonia
R-410A is ozone-friendly and widely adopted as an R-22 replacement.
3. The primary function of the evaporator coil is to:
A. Reject heat to the outdoors
B. Absorb heat from indoor air
C. Compress refrigerant
D. Meter refrigerant flow
The evaporator absorbs heat, causing refrigerant to evaporate.
,4. What electrical device protects a motor from overheating?
A. Contactor
B. Overload protector
C. Transformer
D. Relay
Overload protectors open the circuit when excessive heat or current is
detected.
5. Which law explains the relationship between pressure and temperature of a
gas?
A. Ohm’s Law
B. Boyle’s Law
C. Gay-Lussac’s Law
D. Dalton’s Law
Gay-Lussac’s Law relates pressure and temperature at constant volume.
6. What instrument is used to measure airflow in ducts?
A. Manifold gauge
B. Anemometer
C. Thermocouple
D. Hygrometer
Anemometers measure air velocity and airflow.
7. Which component meters refrigerant into the evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
The expansion device controls refrigerant flow and pressure drop.
8. What is the purpose of superheating refrigerant vapor?
A. Increase pressure
B. Prevent liquid refrigerant from entering the compressor
C. Increase cooling capacity
, D. Reduce airflow
Superheat ensures only vapor reaches the compressor.
9. Which material is commonly used for refrigerant piping?
A. PVC
B. Steel
C. Copper
D. Aluminum
Copper is durable, corrosion-resistant, and easy to braze.
10.A short cycling compressor is most often caused by:
A. Low airflow
B. Faulty thermostat or pressure control
C. Dirty condenser coil
D. Oversized ductwork
Defective controls commonly cause rapid on-off cycling.
11.What device steps down voltage in control circuits?
A. Contactor
B. Transformer
C. Relay
D. Capacitor
Transformers reduce line voltage for safe control operation.
12.Which HVAC system provides both heating and cooling using the same
refrigeration cycle?
A. Furnace
B. Heat pump
C. Boiler
D. Chiller
Heat pumps reverse refrigerant flow for heating or cooling.
13.What does SEER measure?
A. Heating output
B. Cooling efficiency
AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which component is responsible for circulating refrigerant through the
HVAC system?
A. Evaporator
B. Condenser
C. Compressor
D. Expansion valve
The compressor pumps refrigerant through the system, enabling heat
transfer.
2. What type of refrigerant is commonly used as a replacement for R-22 in
residential systems?
A. R-12
B. R-410A
C. R-134a
D. Ammonia
R-410A is ozone-friendly and widely adopted as an R-22 replacement.
3. The primary function of the evaporator coil is to:
A. Reject heat to the outdoors
B. Absorb heat from indoor air
C. Compress refrigerant
D. Meter refrigerant flow
The evaporator absorbs heat, causing refrigerant to evaporate.
,4. What electrical device protects a motor from overheating?
A. Contactor
B. Overload protector
C. Transformer
D. Relay
Overload protectors open the circuit when excessive heat or current is
detected.
5. Which law explains the relationship between pressure and temperature of a
gas?
A. Ohm’s Law
B. Boyle’s Law
C. Gay-Lussac’s Law
D. Dalton’s Law
Gay-Lussac’s Law relates pressure and temperature at constant volume.
6. What instrument is used to measure airflow in ducts?
A. Manifold gauge
B. Anemometer
C. Thermocouple
D. Hygrometer
Anemometers measure air velocity and airflow.
7. Which component meters refrigerant into the evaporator?
A. Compressor
B. Condenser
C. Expansion valve
D. Receiver
The expansion device controls refrigerant flow and pressure drop.
8. What is the purpose of superheating refrigerant vapor?
A. Increase pressure
B. Prevent liquid refrigerant from entering the compressor
C. Increase cooling capacity
, D. Reduce airflow
Superheat ensures only vapor reaches the compressor.
9. Which material is commonly used for refrigerant piping?
A. PVC
B. Steel
C. Copper
D. Aluminum
Copper is durable, corrosion-resistant, and easy to braze.
10.A short cycling compressor is most often caused by:
A. Low airflow
B. Faulty thermostat or pressure control
C. Dirty condenser coil
D. Oversized ductwork
Defective controls commonly cause rapid on-off cycling.
11.What device steps down voltage in control circuits?
A. Contactor
B. Transformer
C. Relay
D. Capacitor
Transformers reduce line voltage for safe control operation.
12.Which HVAC system provides both heating and cooling using the same
refrigeration cycle?
A. Furnace
B. Heat pump
C. Boiler
D. Chiller
Heat pumps reverse refrigerant flow for heating or cooling.
13.What does SEER measure?
A. Heating output
B. Cooling efficiency
